Thread: Alumina powder for finishing?

Has anyone tried alumina (aluminum oxide) powder to paste a strop for finishing instead of diamond or CrO? I have access to 3 micron and 1 micron alumina powders/suspensions, and was wondering if they were worth a shot. (I also have a sample of CrO coming, so once I have a little more experience I might be able to do a direct comparison myself.)

I have used some aluminum oxide paste, but didn't get any results. Unfortunately for the purpose of your question, I probably didn't get any results because my blades were not sharp enough to take to the paste yet.

Depends on what you are looking to do. If your talking final finishing I would think a really fine grit since alumina is hard stuff. What will you use as a carrier to apply it to your strop?

Originally Posted by thebigspendur

Depends on what you are looking to do. If your talking final finishing I would think a really fine grit since alumina is hard stuff. What will you use as a carrier to apply it to your strop?

Yes, I was imagining using it as a touch-up or as the finishing step, after (or instead of) the Spyderco UF and just before stropping on bare leather, where others might use a CrO-pasted strop. 1 micron is the finest I have on hand, but I have a LOT of it. If it seemed worthwhile, I know where I can get some 0.3 and 0.05 micron, but that would require more of an investment (of effort, time, and money), which would somewhat defeat the purpose.

To be honest, I hadn't thought through all the details, but I was hoping not to buy another strop just yet and so I was imagining trying it out on newspaper. Chrisl says that worked well for him with his CrO. As for the medium, I am open to suggestions, but I intended to apply it like I would CrO powder -- if I got a strop I would probably use strop conditioner. On newspaper would water work? Or some kind of oil? I didn't think to ask Chrisl what he used.

Another possibility I had considered was to put it on the linen side of my daily strop for frequent touch-ups.

Correction: Make that 5 micron and 1 micron alumina I have on hand. They are both in distilled water suspensions. I also have a lot of 1 micron dry powder, which is what I was really planning on using. I assume the 5 micron is too course to be of much use.

The 5 micron is to coarse, the 1 micron is good but a 0.5 micron is better. For a suspension use most any oily compound like hand cream/lotion, corn huskers lotion, GOOP, strop dressing, etc. Do not use to much of the mixture! To much will round an edge.

Thanks, Randy. Would that go for newspaper too? I checked with Chrisl, and he said he was applying the CrO dry to the newspaper so as not to mess up the smoothness of the surface.

Originally Posted by BurnBeGone

Thanks, Randy. Would that go for newspaper too? I checked with Chrisl, and he said he was applying the CrO dry to the newspaper so as not to mess up the smoothness of the surface.

Rely upon ChrisL regarding the newspaper. I have no experience with that.

The 1 micron alumina will work fine - I think that's what the TI white paste uses, only with a waxy carrier. Use it dry on newspaper so it won't wrinkle.

Thanks, m. I guess like everything else I'll just have to try it and see. I don't have much experience (like any), so I probably won't be able to tell the difference between the CrO and the Al2O3 or between the 1 micron and the 0.3 micron, but it sounds like it's at least not going to do any harm so it's worth a shot.

Thanks all for the suggestions and your interest!